Image transmission apparatus and method therefor

ABSTRACT

An image transmission apparatus/method characterized by inputting image data, detecting the motion of the image data, setting a transmission condition of the image data in accordance with the detection of the motion of the image data, processing the image data in accordance with the set transmission condition and transmitting the processed image data. 
     An image transmission apparatus/method characterized by detecting an image pickup condition of the image pickup means for picking up an image, decreasing information amount of image data from the image pickup means, controlling the decreasing operation in accordance with the image pickup condition and transmitting the image data having the information amount decreased. 
     An image transmission apparatus/method characterized by picking up an image to acquire image data, setting an image pickup operation mode, determining a transmission condition of the image data in accordance with the set condition, processing the image data in accordance with the determined transmission condition and transmitting the processed image data.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image transmission apparatus fortransmitting image data and a method therefor.

2. Related Background Art

In the past, in order to watch and listen to video and audio picked upby a VTR built-in video camera or a video camera, the VTR built-in videocamera or the video camera is connected to a monitor through a cord.

Alternatively, in order to wirelessly connect the VTR or the videocamera to the monitor, the VTR or the video camera is connected to atransmission unit which is separate from the VTR built-in video cameraor the video camera and the video and the audio are transmitted byFM-modulated infrared rays.

Recently, it has been proposed to wireless-transmit the video and audiodata picked up by the VTR-built-in video camera or the video camera as adigital signal.

However, in case of the cord connection, the work required to connectthe VTR built-in video camera or the video camera with the monitor istroublesome. Further, because of the cord connection, the freedom ofimage pickup and watching is limited.

On the other hand, in the case of the FM-modulated infrared ray wirelessconnection, since the infrared ray transmission unit is separate, theconnection of the VTR built-in video camera or the video camera with theinfrared ray transmission unit is again needed and problems ofdegradation of information due to shortage of transmitted information,interference and disturbance, restriction to the directivity and shorttransmission distance are involved. Further, since the transmissionamount is limited to a certain amount (for example, 128 Kbits/sec),information which is different from the intention of the user of thevideo camera may be transmitted.

SUMMARY OF THE INVENTION

From the background described above, it is an object of the presentinvention to provide an image transmission apparatus which increases thefreedom of image transmission, improves the operability and canexternally transmit the intended information, and a method therefor.

For this purpose, in accordance with one preferred embodiment, the imagetransmission apparatus/method is characterized by inputting image data,detecting the motion of the image data, setting a transmission conditionof the image data in accordance with the detection of the motion of theimage data, processing the image data in accordance with the settransmission condition and transmitting the processed image data.

Further, in accordance with another preferred embodiment the imagetransmission apparatus/method is characterized by detecting an imagepickup condition of the image pickup means for picking up an image,decreasing the information amount of image data from the image pickupmeans, controlling the decreasing operation in accordance with the imagepickup condition and transmitting the image data having the informationamount decreased.

Further, in accordance with another preferred embodiment, the imagetransmission apparatus/method is characterized by picking up an image toacquire image data, setting an image pickup operation mode, determininga transmission condition of the image data in accordance with the setcondition, processing the image data in accordance with the determinedtransmission condition and transmitting the processed image data.

Other objects, features and advantages of the invention will becomeapparent from the following detailed description taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram of a configuration of a VTR built-in videocamera in accordance with the present invention,

FIG. 2 shows a block diagram of detail of a compressionencoding/decoding circuit 108 of FIG. 1,

FIG. 3 shows a block diagram of a configuration of a spread spectrumtransmission circuit 110 of FIG. 1,

FIG. 4 shows a block diagram of a detailed configuration of a pan/tiltdetection circuit 113 of FIG. 1,

FIG. 5 shows an operation flow chart of a pan/tilt detector 404,

FIG. 6 shows a block diagram of a detailed configuration of a motiondetection circuit 116,

FIG. 7 shows a transmission method of image data in an operation key 113and an operation switch for image pickup/transmission mode selection oftransmission image quality,

FIG. 8 illustrates a setting ratio of parameters in an imagepickup/operation mode in an embodiment,

FIG. 9 shows a flow chart of an operation of the VTR built-in videocamera by the operation key shown in FIG. 7,

FIGS. 10A and 10B show examples of display of an EVF 112 in anembodiment,

FIG. 11 shows a block diagram of a configuration of a receiver in anembodiment,

FIG. 12 shows another embodiment of a transmission method of image datain the operation switch 113 and the operation switch for the imagepickup/transmission mode selection of the transmission image quality,and

FIGS. 13A and 13B show relations between the number of frames and aframe rate in a frame preference mode and a resolution preference mode.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The image transmission apparatus of the present invention is nowexplained in connection with a VTR built-in video camera.

FIG. 1 shows a block diagram of a configuration of a VTR built-in videocamera in accordance with the present invention.

In FIG. 1, numeral 101 denotes a lens for picking up an image, numeral102 denotes an image pickup element for focusing the image, numeral 103denotes a CDS (dual correlation sampling)/AGC (automatic gain control)for sampling and holding the image and amplifying it to an appropriatelevel, numeral 104 denotes a motor driver for driving a lens forfocusing or zooming, numeral 105 denotes a digital signal processingcircuit for digitally processing image data, numeral 106 denotes acontrol circuit for controlling peripheral blocks, numeral 107 denotes amemory for digital processing, numeral 108 denotes a compressionencoding/decoding circuit for compressing and decompressing the imagedata, numeral 109 denotes a recording and reproducing apparatus (VTR)for recording and reproducing the image data, numeral 110 denotes aspread spectrum transmission circuit for transmitting the image data,numeral 111 denotes an antenna, numeral 112 denotes an electronic viewfinder for displaying an image and image pickup information, numeral 113denotes an operation key, numeral 114 denotes a microcomputer forcontrolling a system, numeral 115 denotes a detection circuit fordetecting pan or tilt of the VTR built-in video camera and numeral 116denotes a motion detection circuit for detecting the motion of the imagedata.

An operation of the VTR built-in video camera thus configured will beexplained later.

FIG. 2 shows a block diagram of the detail of the compressionencoding/decoding circuit 108 of FIG. 1.

In FIG. 2, numeral 151 denotes a pixel thinning-out circuit, numeral 152denotes a memory, numeral 153 denotes a frame thinning-out circuit forthinning out the number of frames per second of the image data from astandard number, numeral 154 denotes a DCT (discrete cosinetransform)/IDCT (inverse discrete cosine transform) circuit, numeral 155denotes a quantization/inverse-quantization circuit, numeral 156 denotesa quantization step control circuit for controlling a quantization stepof the quantization/inverse-quantization circuit 155, numeral 157denotes a Huffman code/decode circuit and numeral 158 denotes a Huffmantable.

An operation of the compression encoding/decoding circuit 108 thusconfigured is described below.

First, an encoding operation is explained.

The image data inputted to the compression encoding/decoding circuit 108is supplied to the pixel thinning-out circuit 151 and the pixels arethinned out in accordance with control data from the control circuit106.

The image data outputted from the pixel thinning-out circuit 151 istemporarily stored in the memory 152. The frame thinning-out circuit 153reads the image data stored in the memory 152 and thins out the framesin accordance with control data from the control circuit 106.

The image data outputted from the frame thinning-out circuit 153 isdivided into blocks for every 8×8 pixels by the DCT/IDCT circuit 154 toconduct the DCT conversion for each block. The DCT converted image datais supplied to the quantization/inverse-quantization circuit 155 and thequantization step control circuit 156.

The quantization step control circuit 156 collects a plurality of blocksof DCT converted image data, determines the quantization step such thata predetermined code amount is acquired when the plurality of blocks ofimage data are coded and outputs quantization step data indicating thedetermined quantization step to the quantization/inverse-quantizationcircuit 155 and the control circuit 106.

The quantization step data is added to the coded image data by thecontrol circuit 106 and transmitted to a succeeding stage circuit.

The quantization step control circuit 156 is controlled by the controldata from the control circuit 106 as the pixel thinning-out circuit 151and the frame thinning-out circuits are controlled also.

Operation controls of the pixel thinning-out circuit 151, the framethinning-out circuit 153 and the quantization step control circuit 156by the control data from the quantization step control circuit 156 willbe explained later.

In the quantization/inverse-quantization circuit 155, the DCT convertedimage data is quantized by using the quantization step data from thequantization step control circuit 154. The image data quantized by thequantization/inverse-quantization circuit 155 is Huffman-coded by theHuffman code/decode circuit 153 by using the Huffman table 158 and it isoutputted.

The decode operation is now explained.

The coded image data is Huffman-decoded by the Huffman code/decodecircuit 157 in accordance with the Huffman table 158.

The Huffman-decoded image data is dequantized by thequantization/inverse-quantization circuit 155. The quantization step isset by the quantization step control circuit 156 based on the result ofidentification conducted by the control circuit 106 which identifies thequantization step data added to the coded image data and transmitted.

The image data dequantized by the quantization/inverse-quantizationcircuit 155 is IDCT-transformed by the DCT/IDCT circuit 154 and it isoutputted.

FIG. 3 shows a block diagram of a detailed configuration of the speedspectrum transmission circuit 110 of FIG. 1.

In FIG. 3, numeral 301 denotes a serial-parallel converter fromserial-parallel converting the image data, numeral 301-1 to 302-n denotemultipliers, numeral 303 denotes a spread code generator, numeral 304denotes an adder and numeral 305 denotes an RF (radio frequency)converter for converting into an RF signal.

An operation of the spread spectrum transmission circuit 110 thusconfigured is now explained.

The input image data is converted to n parallel data by theserial-parallel converter 301 and the respective converted data aremultiplied by n different spread code outputs of the spread codegenerator 303 in the n multipliers 302-1 to 302-n, added by the adderand outputted to the RF converter 305. The added base band wide spreadsignal is converted to a transmission frequency signal having a propercenter frequency by the RF converter 305 and outputted from thetransmission antenna 111.

FIG. 4 shows a block diagram of a detailed configuration of the pan/tiltdetection circuit 115 of FIG. 1.

In FIG. 4, numeral 401 denotes an angular velocity sensor, numeral 402denotes an amplifier/filter for amplifying the output of the angularvelocity sensor 401 and limiting a band of the signal, numeral 403denotes an A/D converter for converting the analog output of theamplifier/filter 402 to a digital signal and numeral 404 denotes apan/tilt detection circuit for detecting the pan and the tilt of thecamera shown in FIG. 1 based on the output of the A/D converter 403.

An operation of the pan/tilt detection circuit 115 thus configured isnow explained.

When the orientation of the camera is changed by the pan or the tilt,the angle sensor 401 outputs a signal in accordance with an angularvelocity of the change of the orientation.

The output of the angular velocity sensor 401 is amplified andband-limited by the amplifier/filter 402, digitized by the A/D converter403 and inputted to the pan/tilt detection circuit 404.

FIG. 5 shows an operation flow chart of the pan/tilt detector 404.

First, it determines whether the angular velocity is not smaller than apredetermined threshold ωa or not (S1), and if the angular velocity isnot smaller than the threshold ωa, it is determined as the pan/tiltcondition (S2). If an angular displacement which is an integration ofthe angular velocity is not smaller than a threshold ea even if theangular velocity is smaller than the threshold ωa (S3), it is alsodetermined as the pan/tilt condition (S2). If the angular displacementis smaller than Θa, it is determined as a steady state (S4).

The detection result by the pan/tilt detection circuit 404 is applied tothe pixel thinning-out circuit 151 and the frame thinning-out circuit153 and used for the control of the number of thinning-out of the pixelsand the number of thinning-out of the frames.

FIG. 6 shows a block diagram of a detailed configuration of the motiondetection circuit 116.

In FIG. 6, numerals 601 and 603 denote a block divider for dividing thedata into 16×16 pixel blocks, numeral 602 denotes a one-field delaycircuit or delaying the input image data by one field period, numeral604 denotes a matching circuit for matching the outputs from the blockdividers 601 and 603 for each block to calculate a correlationdistribution, numeral 605 denotes a motion vector detector forcalculating a motion vector of each block based on the output from thematching circuit, numeral 606 denotes a weighting circuit for applying apredetermined weight to the motion vector of each block and numeral 607denotes a motion/still image detector for detecting whether the currentimage is a motion image or a still image based on the output of theweighting circuit 606.

An operation of the motion detection circuit 116 thus configured is nowexplained.

The image data inputted from the control circuit 106 is divided into16×16 pixel blocks by the block divider 601. The input image data isalso delayed by one field by the one-field delay circuit 602 and dividedinto 16×16 pixel blocks by the block divider 603 as the block divider601 does.

The matching circuit 604 matches the outputs of the block dividers 601and 603 for each block to calculate the correlation distribution. Themotion vector detector 605 for each block calculates the motion vectorfor each block from the correlation distribution calculated by thematching circuit 604.

A predetermined weight is applied to the motion vector of each blockdetected by the motion detector 605.

For example, a large weight is applied to a center of the screen and asmall weight is applied to a periphery of the screen. Namely, the centerof the screen is weighted.

The motion-still image detector 607 detects whether a current image is amotion picture or a still picture in accordance with the output of theweighting circuit 606. The detection result of the motion/still imagedetector 607 is transmitted to the pixel thinning-out circuit 151 andthe frame thinning-out circuit 153 through the control circuit 106.

An operation of the VTR built-in video camera configured as shown inFIG. 1 is now explained.

In the configuration of FIG. 1, the operation of the VTR built-in videocamera is conducted through the operation key 113.

In the pickup mode of the video camera, an object image is focused on animage pickup element 102 (for example, a CCD) by the lens 101.

The image data derived from the image pickup element 102 is sampled andamplified by the CDS/AGC circuit 103 and inputted to the digital signalprocessing circuit 105. The digital signal processing circuit 105conducts the gamma processing and the white balance adjustment to theinput image data.

The lens 101 receives a control command of the microcomputer 114 for thezooming and the focusing and is driven by the motor driver 104. Theimage data is transmitted from the digital signal processing circuit 105to the EVF 112 for monitoring the image being picked up and the imagepickup data. The image pickup data (for example, tape counter, variousalarms and image pickup operation mode) and control command aretransmitted from the microcomputer 114 to the EVF 112.

On the other hand, the image data is coded by the compressionencoding/decoding circuit 108 by using the control circuit 106 and thememory 107 and recorded in the recording and reproducing circuit 109.

Based on the information set by the user of the video camera by theoperation switch 135 on the operation key 113 of the main unit, codeddata for transmission and timing are generated by using the digitalsignal processing circuit 105, the control circuit 106, the memory 107,the compression encoding/decoding circuit 108, the microcomputer 114,the pan/tilt detection circuit 115 and the motion detection circuit 116and the image data to be transmitted is wireless transmitted from theantenna 111 by the spread spectrum transmission circuit 110 by the settransmission method and transmission image quality.

FIG. 7 shows the transmission method of the image data in the operationkey 113 and the operation switch for the image pickup/transmission modeselection of the transmission image quality.

By operating the operation key 113 of FIG. 7, a user desired image canbe transmitted even for the wireless transmission in which a maximumtransmission rate is smaller than that of wire transmission.

As the image pickup/transmission mode switches, a manual/standardselection switch 701, a sports mode (a frame rate preference mode)selection switch 702, a portrait mode (a resolution preference mode)selection switch 703 and a fault mode selection switch 704 are provided.

The manual/standard mode selection switch 701 switches the manual modeand the standard mode for each operation. When the manual/standard modeselection switch 701 is operated when the sports mode (frame ratepreference mode), the portrait mode (resolution preference mode) or thefault mode is set, the mode is switched to the standard mode.

The respective modes are now explained.

The parameters which can be set in the manual mode include a horizontalimage angle size, a vertical image angle size, the number of pixels perframe, a frame rate (the number of frames/second), a compression rate ofa luminance signal and a compression rate of a color signal. Therespective parameters may be set in various manners by operating slideswitches 705 to 710.

The parameters which may be set by the slide switches are not limited tothe above and switches for various parameters for the transmission suchas an audio compression ratio, a transmission protocol and atransmission power may be provided.

In the sports mode, the portrait mode and the fault mode, the settingratios of the number of pixels, the frame rate and the compression rateare different.

FIG. 8 illustrates the setting ratios of the parameters in the sportsmode (frame rate preference mode), the portrait mode (resolutionpreference mode) and the fault mode.

In FIG. 8, an abscissa represents the parameters (compression ratio,frame rate and the number of pixels) and an ordinate represents themagnitude of numerals.

In the standard mode, the ratio A is set, and in the sports mode (framerate preference mode), the ratio B for the preference of the frame modeis set and the number of pixels is reduced from the standard by thecontrol of the pixel thinning-out circuit 151, and the weighting isapplied to the quantization step by the quantization step controlcircuit 156 to increase the frame rate. In the sports mode, the framerate may be controlled to increase by increasing the compression ratiowithout reducing the number of pixels. The frame rate by the sports modeis a maximum frame rate (for example, 30 frames/second) which can beattained by the video camera.

In the portrait mode (resolution preference mode), the ratio is set to Cfor the preference of the resolution, and the number of pixels isincreased from the standard by the control of the pixel thinning-outcircuit 151, the frame rate is reduced from the standard by the controlof the frame rate thinning-out circuit 153, and the weighting is appliedto the quantization step by the quantization step control circuit 156 toreduce the compression ratio from the standard. By this process, a highresolution and high quality image is attained although the frame rate isdropped.

When the sports mode or the portrait mode is set when the image data isto be transmitted together with the image pickup of the VTR built-invideo camera, a charge storage time of the image pickup element 102 isset shorter than that in the standard mode by the microcomputer 114 andan object depth is set shallow. A focus following velocity of the lens101 driven through the motor driver 104 is fastest in the sports mode,next fastest in the standard mode and slowest in., the portrait mode. Ina full auto mode, the image pickup element 102 and the motor driver 104operate in the same manner as that in the standard mode as opposed tothe sports mode and the portrait mode.

FIGS. 13A and 13B show relations between the number of pixels and theframe rate in the frame preference mode and the resolution preferencemode in the present embodiment.

In the fault mode, whether the image is a motion image or a still imageis determined by the pan/tilt detection circuit 115 and the motiondetection circuit 116, and when it is the motion image, the pixelthinning-out circuit 151, the frame rate thinning-out circuit 153 andthe quantization step control circuit 156 are controlled to set theratio B, and when it is the still image, they are controlled to set theratio C.

Namely, in the fault mode, the frame preference mode or the resolutionpreference mode is automatically selected in accordance with the motionof the image.

In the present embodiment, the manual mode, the standard mode, thesports mode (frame rate preference mode), the portrait mode (resolutionpreference mode) and the fault mode are shown as the imagepickup/transmission modes, the ratios of the parameters may beprogrammed in other operation modes for setting the image quality. As tothe sorts of the parameters, parameters such as audio compression ratio,transmission protocol and transmission power may be used.

A wireless transmission operation of the VTR built-in video camera usingthe operation key shown in FIG. 7 is now explained with reference to aflow chart of FIG. 9.

FIG. 9 shows a flow chart of an operation of the VTR built-in videocamera by the operation switch shown in FIG. 7.

First, in a step S11, a state of the operation switch (see FIG. 7)operated by the user of the video camera is read.

In a step S12, whether the manual mode is set or not is determined. Ifthe manual mode is set, the process proceeds to a step S13 to read theset states of the slide switches 705 to 710 shown in FIG. 7 to determinethe settings to control the pixel thinning-out circuit 151, the framerate thinning-out circuit 153 and the quantization step control circuit156.

In the step S12, if the manual mode is not set, the process proceeds toa step S14 to determine whether the standard mode is set or not. If thestandard mode is set, the process proceeds to a step S15 to determinethe setting to control the pixel thinning-out circuit 151, the framerate thinning-out circuit 153 and the quantization step control circuit156 to set the setting ratio A of FIG. 8.

In the step S14, if the standard mode is not set, the process proceedsto a step S16 to determine whether the sports mode (frame ratepreference mode) is set or not. If the sports mode (frame ratepreference mode) is set, the process proceeds to a step S17 to determinethe setting to control the pixel thinning-out circuit 151, the framerate thinning-out circuit 153 and the quantization step control circuit156 to set the setting ratio B of FIG. 8, and the process proceeds to astep S24.

In the step S16, if the sports mode (frame rate preference mode) is notset, the process proceeds to a step S18 to determine whether theportrait mode (resolution preference mode) is set or not. If theportrait mode (resolution preference mode) is set, the process proceedsto a step S19 to determine the settings to control the pixelthinning-out circuit 151, the frame rate thinning-out circuit 153 andthe quantization step control circuit 156 to set the setting ratio C ofFIG. 8, and the process proceeds to a step S24.

In the step S18, if the portrait mode (resolution preference mode) isnot set, the process proceeds to a step S20 to determine whether thefault mode is set or not. If the fault mode is set, the process proceedsto a step S21 to determine whether the input image data is a motionimage or not.

In the determination method for the motion image in the step S21,whether the input image data is a motion image or not is determined bydetermining whether the pan/tilt state is set or not by the pan/tiltdetection circuit.

Namely, when it is determined as the pan/tilt state by the pan/tiltdetection circuit 115, it is determined that the input image data is amotion image. If it is not the pan/tilt state, whether the input imagedata is a motion picture or not is determined by the motion detection bythe motion detection circuit 116.

If it is determined as the motion image in the step S21, the processproceeds to a step S22 to determine the setting to control the pixelthinning-out circuit 151, the frame rate th inning-out circuit 153 andthe quantization step control circuit 156 to set the setting ratio B ofFIG. 8 and the process proceeds to a step S24.

If it is determined as not a motion image in the step S21, the processproceeds to a step S23 to determine the settings to control the pixelthinning-out circuit 151, the frame rate thinning-out circuit 153 andthe quantization step control circuit 156 to set the setting ratio C ofFIG. 8, and the process proceeds to a step S24.

If the fault mode is not set in the step S20, the process returns to thestep S11 to read the state of the operation switch (see FIG. 7) toconduct the mode determination again.

In the step S24, the operations of the pixel thinning-out circuit 151,the frame rate thinning-out circuit 153 and the quantization stepcontrol circuit 156 are controlled to set the settings determined in thesteps S15, S17, S19, S22 and S23.

In a step S25, whether the transmission data is within a transmissioncapacity or not is determined. If it exceeds the transmission capacity,the process proceeds to a step S26 to control the quantization stepcontrol circuit 156 to adjust the quantization step to suppress thetransmission data amount within the transmission capacity.

In the step S25, if it is within the transmission capacity, the processproceeds to a step S27 to start the data transmission.

In a step S28, whether the data transmission is completed or not isdetermined, and if the data transmission is not completed, the processreturns to the step S11. If the data transmission is completed, the flowis terminated.

The settings determined in the steps S15, S17, S19, S21, S23 and S22 arestored in a ROM table built in the system in the present embodiment.

In the present embodiment, an operation state of the camera is displayedon the EVF 112 to allow the user of the video camera to recognize theoperation state of the video camera.

FIGS. 10A and 10B show examples of the display of the EVF 112 of theembodiment.

FIG. 10A shows an example of the display of the EVF 112 in the manualmode and FIG. 10B shows an example of the display of the EVF 112 in thesports mode.

“Record” in the figure indicates a recorder operation mode in the VTRbuilt-in video camera and “10:15 AM” and “1995.12.10” indicates an autodate.

An apparats for receiving the data wireless transmitted by the VTRbuilt-in video camera of FIG. 1 is now explained.

FIG. 11 shows a block diagram of a configuration of a receivingapparatus in the embodiment.

In FIG. 11, numeral 201 denotes an antenna, numeral 202 denotes a spreadspectrum receiving circuit for spectrum inverse-spreading the signalreceived by the antenna 201 (by correlating the received signal with thesame spread signal as that of the transmitter), converting the receivedsignal to a narrow band signal having a band width corresponding to theoriginal data and conducting the normal data demodulation to reproducethe original data. Numeral 203 denotes a decoding circuit fordemodulating the image data reproduced by the spread spectrum receivingcircuit 202, numeral 204 denotes an input buffer for temporarily storingthe decoded image data, numeral 205 denotes a frame memory for storingone frame of image data, and numeral 206 denotes a recording andreproducing circuit for temporarily storing the image data outputtedfrom the frame memory 205 in a recording medium and reproducing it asrequired. Numeral 207 denotes a synchronization signal addition circuitfor adding video synchronization signal data to the image data read fromthe frame memory 205 to convert it to video data, numeral 208 denotes aD/A converter, numeral 209 denotes a monitor (for example, a liquidcrystal monitor) for video-displaying the video signal outputted fromthe D/A converter 208, numeral 210 denotes a frame control circuit forcontrolling the input buffer 204 and the frame memory 205 and outputtingone frame of received image data from the frame memory 205 and numeral211 denotes a synchronization signal generation circuit for generating asynchronization signal for defining a timing of the overall system and avideo synchronization signal of the received image data.

An operation of the receiving apparatus thus configured is nowexplained.

The spread spectrum receiving circuit 202 spectrum inverse-spreads thesignal received by the antenna 201 to convert the received signal to anarrow band signal of the band width of the original data to demodulatethe original data.

The demodulated image data is supplied to the decoding circuit 203 fordecoding processing. The decoded image data is stored in the framememory 205 through the input buffer 204. When the frame memory 205stores one frame of image data, it reads out the image data.

The image data read out from the frame memory 205 is supplied to thesynchronization signal addition circuit 207 or recorded and reproducedby the recording and reproducing circuit 206 and then supplied to thesynchronization signal addition circuit 207.

The synchronization signal addition circuit 207 adds the videosynchronization signal data from the synchronization signal generationcircuit 211 to the image data from the frame memory 205 or the recordingand reproducing circuit 206. The D/A converter 208 converts the digitaloutput of the synchronization signal addition circuit 207 to an analogsignal and supplies it to the LCD monitor 209. The LCD monitor 209displays the supplied image signal.

As described herein above, in accordance with the present embodiment,since the wireless transmission is conducted by freely selecting thetransmission method and the transmission image quality which the user ofthe video camera desires, the information desired by the user of thevideo camera may be transmitted. Further, since the information of theoptimum transmission method and the transmission image quality isautomatically generated in accordance with the operation mode in theimage pickup mode and it is wireless transmitted, the work of the userof the video camera may be saved and the optimum wireless transmissionmay be conducted.

Further, since the spread spectrum transmission system is used for thewireless transmission, the transmission information amount may beincreased, the degradation of the information by interference anddisturbance may be prevented, the directivity is enhanced and thetransmission distance may be extended. Further, since the settinginformation is displayed in the finder, the failure of the transmissionstate may be prevented and the operability is improved.

The operation switch of the present embodiment shown in FIG. 7 is a mereexample and various forms may be adopted.

For example, another example is shown in FIG. 12. The operation switchof FIG. 12 uses one rotary switch 720 as a switch to set in the manualmode.

When the rotary switch 720 is rotated to a position a, the preference isset to the frame rate, and when it is rotated to a position b, thepreference is set to the resolution.

As the rotary switch 720 is operated, the control circuit 106 controlsthe pixel thinning-out circuit 151, the frame rate thinning-out circuit153 and the quantization step control circuit 156.

In other words, the foregoing description of the embodiments has beengiven for illustrative purposes only and is not to be construed asimposing any limitation in every respect.

The scope of the invention is, therefore, to be determined solely by thefollowing claims and not limited by the text of the specification andalterations made within a scope equivalent to the scope of the claimsfall within the true spirit and scope of the invention.

What is claimed is:
 1. An image transmission apparatus comprising: imagepickup means for picking up an image to output moving image data, saidimage pickup means having a plurality of image pickup operation modesfor performing different image pickup processings, respectively; settingmeans for setting an image pickup operation mode from among theplurality of image pickup operation modes; control means for controllinga frame rate and a resolution of the moving image data in accordancewith the image pickup operation mode set by said setting means, saidcontrol means controlling the resolution so that the resolutionincreases or decreases when the frame rate is decreased or increased;and transmission means for transmitting the moving image data controlledby said control means.
 2. Apparatus according to claim 1, wherein saidtransmission means comprises wireless transmission means.
 3. Apparatusaccording to claim 2, wherein said wireless transmission means comprisesa spread spectrum system.
 4. Apparatus according to claim 1, whereinsaid transmission means includes coding means for compression-encodingthe moving image data, said coding means controlling a code amount ofthe moving image data according to the image pickup operation mode setby said setting means.
 5. Apparatus according to claim 1, wherein saidimage pickup means includes an image pickup element, and wherein, ineach of the plurality of image pickup operation modes, the image pickupelement uses a different charge accumulation time.
 6. Apparatusaccording to claim 1, wherein said image pickup means includes a lens,and wherein, in each of the plurality of image pickup operation modes,the lens uses a different moving speed.
 7. Apparatus according to claim1, wherein each of the plurality of image pickup operation modes uses adifferent depth of field.
 8. An image transmission method comprising thesteps of: picking up an image to output moving image data by using animage pickup unit, said image pickup unit having a plurality of imagepickup operation modes for performing different image pickupprocessings, respectively; setting an image pickup operation mode fromamong the plurality of image pickup operation modes; controlling a framerate and a resolution of the moving image data in accordance with theimage pickup operation mode set in said setting step, said control stepincluding a step of controlling the resolution so that the resolutionincreases or decreases when the frame rate is decreased or increased;and transmitting the moving image data controlled in said frame ratecontrol step.